Supergirl‘s season-long villain arc finally came to a head in “Reign,” and the destruction is widespread and devastating. Not only did Kara (Melissa Benoist) have to contend with her toughest enemy yet, she also had to watch Mon-El (Chris Wood) move on before her very eyes. But the night did not pass without spreading some Christmas cheer, as the slow build of Lena (Katie McGrath) and James’ (Mehcad Brooks) flirtation reached its happy-for-now conclusion.

A bond only a Kryptonian Devil can weaken.

“Reign” starts off sweetly enough, with Kara planning her Holiday party and inviting Mon-El and his wife Imra to join the festivities. They blessedly decline, because no one wants to deal with that emotional train wreck, so instead Kara and Alex (Chyler Leigh) celebrate a future of being crones together. Their adorable sisterly interactions are superseded only by the wonderful friendship that has blossomed between Kara, Lena, and Sam (Odette Annable). One of the best scenes in this week’s Supergirl consists simply of the three gals gossiping about James at the party, then cementing the importance of their friendship with a sincerity that nearly brought me to tears.

Unfortunately, the strength of that friendship is not enough for Sam to open up about the Reign of it all – though to be fair, that’s because she doesn’t even know what’s happening to her. Ruby can tell something is off with her mother, and young Emma Tremblay does an excellent job of portraying all the pain and confusion of a daughter slowly losing the only parent she has. Annable also shines in these heart-wrenching scenes, and the more fiercely her love for her child comes across the more traumatic it is to watch her slip away. Once again, my only issue with this storyline remains the questions that arise from it. Is Reign part of Sam or another entity that has taken over her? If it’s the former, then what activated her and why don’t the two sides of her come together as one? And if it’s the latter, then why is Sam specifically the one meant to become Reign?

At least the cult-tastic Thomas Coville (guest star Chad Lowe) is back to provide Kara and the audience with some answers. His creepy religious babble about Reign basically being the Devil set the scene for the episode’s final showdown, and definitely helped raise the stakes for Kara. There were some other great touches as well that turned the tension up to twelve, such as a perfect parallel of Sam ripping off her shirt to reveal the Reign symbol underneath that proved her more of a dark reflection of Kara than Overgirl could ever be. There’s still no hint of anyone – save for perhaps poor Ruby – connecting the dots between the new Kryptonian nightmare and Sam, but the house of cards is perfectly set up to come crashing down in the back half.

Speaking of crashing down, my biggest qualm with Supergirl this season is how much it’s wasting its other heroes. Kara now has three super-powered friends holed up at the DEO; technically four if we count M’yrnn, but we’ll let him slide because he was just held prisoner for hundreds of years. Two of those even participated in a Legion of Superheroes to honor Kara’s legacy in the 31st century. Yet not a single one of them could participate in Kara’s otherwise amazingly directed and choreographed battle against Reign? As the holiday jingles hilariously clashed with a National City office getting torn to shreds by two Kryptonian superwomen, I couldn’t help but wonder why Mon-El or J’onn (David Harewood) didn’t want to help out. Of course it’s not a character choice for them, but it sure takes one out of the moment.

Two angels who deserve the world.

Meanwhile, James and Lena’s subplot was adorable and moved at an appropriate pace – even if I myself was rooting for Kara and Lena before this season. There have been hints of an attraction brewing between them for weeks, and though it was a little cheesy for other characters to actively call it out, their sweet chemistry more than made up for it. Some have pointed to James’ previous mistrust of Luthors as a reason to disapprove of the pairing, but this episode showcased just how far both he and Lena had moved beyond their initial misconceptions of each other. The progress in their dynamic was encapsulated when Lena announced that she believed Morgan Edge was harassing her once again and James took her at her word, even offering to join her for a confrontation. Similarly, she disagreed somewhat with how he was handling the “evil” Kryptonian messages at CatCo, but did not interfere in his job and instead asked for help in uncovering the people responsible. While we can’t be sure how invested the Supergirlwriters are in this pairing so far, it’s a darling interlude at the moment.

Less darling is the song and dance between Kara and Mon-El, which slows down the narrative quite a bit despite being an excellent opportunity for Benoist to pull off silent moments of hurt and heartbreak. Having to watch Kara adjust to the man she loves being in love with someone else is painful, but it doesn’t seem to be leading anywhere. Mon-El shows no signs of secretly pining for his ex as of yet, and neither he nor his wife have shown any of those superhero skills they supposedly picked up in the 31st century. Hopefully they break open those pods soon, so that the purpose of their return can become clear.

“Reign” ended the night in the most destructive way possible, knocking Kara out and leaving her fighting for her life. As shocking and impressive as the final sequence was, there are still a lot of questions the back half needs to answer to make Supergirl‘s latest Big Bad its most effective one yet.